I have a javax.json.JsonObject and want to validate it against a JSON schema. So I've found the com.github.fge.json-schema-validator. But it works only with com.fasterxml.jackson.databind.JsonNode.
Is there a way to convert my JsonObject into a JsonNode?
public JsonNode toJsonNode(JsonObject jsonObj) { ObjectMapper objectMapper = new ObjectMapper(); return objectMapper.readTree(jsonObj.toString()); } this will just to it. JsonObject.toString() will convert to json String, you don't need to use anything else.
The following solution parses a javax.json.JsonObject into a JSON string and then parses the JSON string into a com.fasterxml.jackson.databind.JsonNode using Jackson's ObjectMapper:
public JsonNode toJsonNode(JsonObject jsonObject) { // Parse a JsonObject into a JSON string StringWriter stringWriter = new StringWriter(); try (JsonWriter jsonWriter = Json.createWriter(stringWriter)) { jsonWriter.writeObject(jsonObject); } String json = stringWriter.toString(); // Parse a JSON string into a JsonNode ObjectMapper objectMapper = new ObjectMapper(); JsonNode jsonNode = objectMapper.readTree(json); return jsonNode; } 
javax.json.Json. It's part of the Java EE 7 and was introduced in the JSR 353, the Java API for JSON Processing.